The recent spate of rail strikes means trade union law may have to be made tougher, Conservative leader Iain Duncan Smith has hinted.

Speaking at a lunch with female political journalists, the Tory leader indicated he wanted a review of anti-strike laws because public service unions were "flexing their muscles".

Tony Blair's language now seems to suggest that the unions will have an easier time in future rather than a tougher time

Iain Duncan Smith

Mr Duncan Smith argued the government's language suggested unions were in for an easier ride.

Government ministers have condemned the rail strikes and the Department of Trade and Industry says fewer days are now being lost through industrial action.

Renewing old measures

Mr Duncan Smith says the government has wrongly watered down much of the laws controlling trade unions introduced during the Thatcher years.

He told the reporters: "We felt that the balance was OK before Labour came in, in terms of requiring pre-strike ballots and allowing employers to dismiss employees who bent the rules."

The Conservative leader suggested he wanted to reinstate such measures but the party's policy review continues and no specific plans have been outlined.

Byers says strikes have no place on modern railways

"Tony Blair's language now seems to suggest that the unions will have an easier time in future rather than a tougher time," he said.

The comments came as commuters faced a second day of delays because of strikes on South West Trains.

The Trades Unions Congress has rebutted suggestions the UK is having a new period of industrial strife similar to that seen in the late 1970s.

That view is backed by Department of Trade and Industry who said in the year to November 2001, the number of days lost through industrial action was 36% of the total for 1996.

In the 1980s, an average of 7.2m days were lost each year to strikes, a DTI spokeswoman told BBC News Online.

'Low' strike rates

The spokeswoman said: "The government has put in place a balanced package of measures on industrial relations and has also been working positively with the CBI and TUC to encourage partnership at work between employers and employees.

"There is no evidence to show that change in the law has encouraged strike action or prolonged disputes.

"Levels of industrial action remain low."

Earlier this month Transport Secretary Stephen Byers said strikes were making services worse for passengers and were in no one's interest.

"Arbitration must be a better way forward than strike action - action which is really just a matter of strength," said Mr Byers.

Mr Duncan Smith last week launched a fierce attack on the government over the NHS, focusing on the treatment given to pensioner Rose Addis.

Health focus

That prompted Tony Blair to accuse the Conservatives of trying to undermine the health service by denigrating everything about it.

The Tory leader, who rejects that charge, said he intended to concentrate his fire on health issues for the moment.

But he said acting on issues like rail strikes was part of his campaign to get the public to see the Tories as straightforward and honest.

Mr Duncan Smith also used the lunchtime speech on Tuesday to pledge there will be more women Conservative candidates at the next general election.

He rejected the idea of quotes or all-women shortlists - which the government has moved to make legal .

Instead, the Tories would profile every constituency and instruct selection panels to ensure women and people from ethnic minorities had a fair chance of being chosen.